Calipers



June 12, 1 928. 1,672,966

A. F; WAHLBERG v CALIPERS Filed April 4, 31927 Patented June 12, 1928 ANDRES 1'. wAnLBEne, or nasal ORANGE, NEW JERSEY.

GALIPERS.

Application filed April 4,

This invention relates to combined calipers and dividers which may be employed ior obtaining the inside and outside measure-- ments with one adjustment. It is possible by means of this instrument to measure the inside dimensions of an opening and simultaneously if desired the outside measure ment of the piston which is to fit within said opening. I j

1 Further detail features of the invent on will be apparent from the following descrlption and will be set forth in the appended claims.

In the drawings:

Figure 1 is a top plan view of the invention showing the same employed for meas uring both inside and outside dimensions.

-Figure 2 is a similar view with parts in section and the legs of the calipers in a different position. I

Figure 3 is a longitudinal section on theline 3-3 of Figure 2.

Figure 4 is a transverse section on the line 4-4 of Figure 2. a

The calipers constituting the subject matter of this invention comprise a pair of members 1 and 2 which are identical in form and which are ivoted together to turn about Ml axis 3. is ivot comprises a screw headed bolt 4 winch passes through both members and through a hollow housing 5 and may be riveted as at 6 on the outside of this housin Other fastening means may as employed if desired.

Coiled about the bolt 4 and within the housing is a spring 7 which has one arm .8 extending through an opening in the housing and bearing against the le 2 of the :alipers while the other end of the spring 9 axtends through a similar opening and bears against the leg 1 of the calipers. This spring tends to force the calipers about the pivotalaxis 8 in the direction indicated by :he arrows in Figure 2.

Posts 10 and 11 are ;he legs 2 and 1 respectively at one side of :he pivotal point and'are held in position 3y screws 12 and 13 respectively or by other similar fastenin means; Each of these oosts'is provide 'with a transverse opening zherethrough in which fits a screw threaded rod 14. On this rod is provided a threaded out 15 between which and one of the posts is interposed a bushing or washer 16. The posts may be provided with thumb screws 17 and 18 respectively as shown in Figure 4 p'ivotally carried by V 1927. Serial No. 180,820.

which ma be screwed down upon the rod 14 t0 .loc the parts in adjusted position. If desired, however, the end of the rod which engages in the posts 10 may be riveted or otherwisefastened in position and in this case the thumb screws 17 and 18 may be omitted. v

One end of each member of the calipers terminates in a sharp point- 19 enabling the same to be employed as dividers. At a point slightly removed" from the end each leg of the calipers has on the outside thereof a projection 20 terminating in a sharp point. The other end of each leg of the calipers is curved inward in the usual manner and terminates in a point 21.

The spring 7 acts to move the calipers toward an open position in which the washer 16 engages against the post 11. Whenever it is desired to adjust the calipers it is only necessary to turn the thumb screw 15 whereupon the calipers will be moved positively toward a closed position or will be allowed to expand to a more open position under the influence. of the spring 7. The points 20 serve for measuring the inside dimensions of 4 a cylindrical-object such as indicated at X, while the points 21 serve for the purpose of measuring the outside dimensions of a pis ton or similar object Y.

One of the important features of the invention resides in the fact that the distance from the axis 3 about which the membersof the calipers move to the points 20 is exactly the same as the distance to the points 21. When the calipers are adjusted so that the points 20 give the desired inside dimension, then the points 21 will measure exactly the same outside dimension. This operation is clearly indicated in Figure 1 of the drawings. Accordingly there is no necessity for reading the particular adjustment of the inside dimensions on a scale and then setting the calipers again for the purpose of reading the outside dimensions. All'likelihood of error in the various adjustments is eliminated and its is possible to measure both inside and outside dimensions simultaneously or in sequence without error.

It is obvious that various details of the precise construction may be modified widely without in any we departing from the spirit of the invention, which is to be regarded aslimited only by the scope of the appended claims 7 I claim as my invention:

5 tion near said end adapted to measure inner u dimensions, the other end of each member being turned inwardly to permit measuring of outer dlmenslons, the inner and outer dimensions measured being the same for each 10 adjustment of the members.

2. Calipers comprisin two similar members, a pivot holding sai members together,

' a post fastened to each member, one of said posts havin an opening therethrough, n screwthrea ed rod fastened to the other post and passing through said opening, 2 screw threaded member onsaid rod and adapted by its adjustment to move one mem ber relativelyio the other in one directioi and a spring having its central portiol coiled about said pivot and its ends engaging said posts for normally tending to move th similar members in the o posite direction.

In testimony whereo I have hereunt subscribed my name.

ANDRES F. WAHLBERG. 

